Improvement in sewing-m ach ines



-2 Sheets-Sheet 1. W. O. GROVER.

Sewing Machine.

. Patented 0ct.'5, 1858.

- o 2 Sheets-Sheet 2. W. GROVER.

Sewing Machine.

No. 21,670. Patented Oct. 5,1858.

mrncna Pholo-UKMagnpMr. Walhingbn. a. c.

UNITED STATES PATENT OFFICE.

V. O. GROVER, OF BOSTO N, MASSACHUSETTS.

IMPROVEMENT lN'SEWlNG-MACHINES.

Specification forming part of Letters Patent No. 21,670, dated(ll-teller 5,

To all whom, it may concern.-

Be it known that 1, WILLIAM O. Gnovnn, of the city of Boston, in theState of Massachusetts, have invented certain new and usefulImprovements in Sewing-Machines, applicable to those classes of machinesin which a curved vibrating needle is employed; and I do hereby declarethat the following specification, taken in connection with the drawings,is a full, clear, and exact description thereof.

In the drawings, Figure 1 is a side elevation of a completesewing-machine. Fig. 2 is a front elevation thereof; and Figs. 3, 4:,and 5 are detail drawings of a modification of the apparatus for drivingor actuating a curved needle, being respectively a rear elevation, aside elevation, and a plan.

The machine represented in the drawings is of that variety which sewes achain-stitch with two threads; but my improvements are applicable toother varieties of sewing-machines; and I wish to premise that what Ishall call throughout this specification a curved or crooked needle isnot such in the usual acceptation of that term, as it does not piercecloth, but performs two offices-one of eausinga turn of thread to beformed around another needle, and another of putting a thread through aloop formed by another needle; and I also wish it clearly understoodthat my actuating mechanism maybe and is intended to be used incombination with what are termed hookers-0n, (in French accroc'hcra)used for presenting a looper bight to a crochet or hook-pointed needle,and also in combination with what are technically known as loopers,which make a crochet-stitch by joint action with an eyepointed needle,such hookers-on and loopers having an interrupted vibratory motion, aswell as the curved needle, which is specifically described in thisspecification; and the nature of my invention consists, first, inactuating a curved needle, looper, or hooker-on having an interruptedvibratory motion by means of the combination of an irregular-shapedspiral shaft with a reciprocating driver, both substantially such andacting substantially in the manner hereinafter specified; second, inmounting a reciprocating driver with one or more springs, substantiallyin the manner and for the purpose specified; third, in combining withsuch springs layers of rawhide, leather, or equiva lent material, forthe purpose desired, snbstantially in the manner and for the purposesspeciiied; and, lastly, in fitting either. springs or stiff pieces ofmaterial or springs compounded with hide, &c., into a driver in suchmanner that they are free to slide in planes perpendicular, or nearlyso, to an irregular shaft, which they surround or embrace, substantiallyin the manner and for the purpose s ecified.

The machine represented in the drawings is one that forms the stitchknown to the trade as the Grover & Baker stitch, and is pro vided with aneedlearm, a, carrying a needle. I), and with proper spool-holders,tension apparatus, feed and driving mechanism, and all necessaryadjuncts for making up a complete sewing-machine, (not described, asthey form no part of this invention,) and also with a crooked needle, 0,which, while sewing, must vibrate through certain arcs at proper times,and must pause or rest at determined intervals for such a period as maybe necessary. This needle is mounted upon one end of an irregular spiralshaft, (1, supported at top and bottom in proper boxes, 0 6, so that itis free to vibrate or rock. This shaft (1, at or near the center of itslength, is formed either somewhat like the American anger, as shown inFigs. 3 and 4, or like an American gimlet, as shown in Figs. 1 and 2,being either a single or double threaded .screw, while the thread orthreads, as the case may be, terminate or gradually run into fiatsurfaces whose planes are parallel, or nearly so, to the axis of theshafts. These flat surfaces are shown at f f. In close proximity to thisshaft is supported a vibrating or reciprocating driver, such as g,mounted in the present instance on a center, and receiving motionthrough some appropriate connection with the driving-shaft. In a properbox or slots in this driver are mounted or confined in any suitablemanner one or more springs, s s, which lie in contact with the flatparts of the shaft or bear against the screw thereof in differentpositions of the driver if the shalt be single-threaded; or, if theshaft be double-threaded, these springs embrace it, as clearly shown inFigs. 3, 4, and 5.

By inspection of the drawings it will be perceived that when the driveris at one end of the shaft and commences to rise, it holds the shaft atrest so long as the springs or drivingsurface rest against the flatsurfaces; but when the springs reach the screw they cause the shaft toturn and rock until they arrive at the fiatl'surface or surfaces at theother end of the shaft, when they will stop its revolution and hold itat rest until the driver by reciproquired are by a proper number ofturns or parts of a turn of a screw-thread, and that its velocity ofvibration will depend upon the pitch of the thread and the speed of thedriver,

and that the time and period of its rests de pend upon the location ofthe flat pieces and their length as compared with the velocity of thedriver. Proper attention to these points will enable a competentmechanic to vibrate the shaft when and to what extent he pleases; and byusing a screw of varying pitch or one with reversed threads he may alsoaccelerate or retard any part of a vibration or cause the sh aft tooscillate backward without any pause. The driver may have a properactuatingsurface formed upon or attached to it, thus dispensing withsprings; but springs serve to diminish the jar occasioned by the driverstriking the screw parts of the shaft on leav ing the flat surfaces, andI have found the best arrangement to consist in letting several piecesof watch or clock spring into an opening in the driver, as shown in thedrawings, and in order to diminish the noise and rattle of these springsI interla'yer them with pieces of rawhide, leather, or other similarmaterial, for the purpose, (see q q, Fig. 4,) which serve also asreservoirs of oil, so that it is not nec essary to apply oil so often tothe points of contact of the shaft and driving-surface.

\Vhen a single-threaded shaft is employed, as shown in Figs. 1. and 2,the springs must be fast in the reciprocating driver or else heldagainst its surface by a spring-pressure; but

- when a double-threaded shaft like that shown in Figs. 3, 4L, and 5 isused, then the springs are to embrace the shaft, being slot-ted out, as.in Fig. 5, and merely rest in'slots in the driver, being free to slidein planes perpendicular to to the shaft, or nearly so. This lattermodification my own experience proves to be the best, as either thedriving-arm or the shaft itself may get materiallyout of adjustmentwithout affecting the proper successful action of the machine, as thesprings will accommo date themselves to any moderate amount of deviationof either shaft or driver from their originally-adjusted position. i

In the drawings the driver is shown as making part of an arm whichvibrates on a center; but it may be attached, supported, and moved inany convenient manner so long as the actuating-surface, whatever it maybe, moves to and fro to a proper distance in contact with the shaft thatcarries the curved needle. This crooked .or curved needle, being firmlysecured to the shaft, partakes of all its oscillations and pauses, andthe precise duty that such needle is required to perform in order to thesuccessful action ofthe machine will, as before referred to, govern theprecise shape of the flattened and screwed shaft, an d the speed andlength of vibration of the actuating-surface of the driver.

Having thus described my improvement, I claim as of my own invention l.The combination, with a curved needle or hooker-on or looper, of anirregularly-shaped spiral shaft and a reciprocating driver, bothsubstantially such as hereinbefore specified, and constituting anapparatus for imparting the required motions and pauses to a crookedneedle, substantially in the manner specified.

2. Mounting a driver, combined with and acting upon a spiral shaft, bothsubstantially such as described, with a spring or springs, substantiallyin the manne and for the purpose specified.

3. Combining such springs with layers of rawhide, leather, or similarmaterial, when acting upon and in combination with a spiral shaft,substantially in the manner and for the purposes specified.

4. An actuating-surface substantially such as is specified, so formedasto surround or embrace an irregular screwed shaft, and at the same timefree to slide in a driver in planes perpendicular, ornearly so, to such.a shaft, substantially in the manner and for the purposes specified.

In testimony whereof I have hereunto subscribed my name, in the city ofBoston, on

this 21st day of December, A. D. 1857.

' I M. 0. GROVER. In presence of- S. G. GORDON,

J AMns H. BROWN.

